# DMPlexSNESComputeJacobianFEM
Form the local portion of the Jacobian matrix J at the local solution X using pointwise functions specified by the user. 
## Synopsis
```
#include "petscdmplex.h" 
#include "petscsnes.h"   
PetscErrorCode DMPlexSNESComputeJacobianFEM(DM dm, Vec X, Mat Jac, Mat JacP, void *user)
```

## Input Parameters

- ***dm -*** The mesh
- ***X  -*** Local input vector
- ***user -*** The user context



## Output Parameter

- ***Jac  -*** Jacobian matrix



## Note
We form the residual one batch of elements at a time. This allows us to offload work onto an accelerator,
like a GPU, or vectorize on a multicore machine.




## See Also
 `DMPLEX`, `Mat`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/utils/dmplexsnes.c.html#DMPlexSNESComputeJacobianFEM">src/snes/utils/dmplexsnes.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/tutorials/ex3.c.html">src/tao/tutorials/ex3.c.html</A><BR>


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[Index of all SNES routines](index.md)  
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[Index of all manual pages](/docs/manualpages/singleindex.md)  
